lib: Add test for stats_dist_get_variance()

diff --git a/src/lib/test-stats-dist.c b/src/lib/test-stats-dist.c
index 9c291624f73d630592056baf5a75aa0d48539611..c15082c7f71a1dfc3e3b63f20242b60541b03575 100644 (file)
--- a/src/lib/test-stats-dist.c
+++ b/src/lib/test-stats-dist.c
@@ -48,6 +48,37 @@ test_stats_dist_verify(const struct stats_dist *t, const int64_t *input,
        i_free(copy);
 }
 
+static void test_stats_dist_get_variance(void)
+{
+       static const struct {
+               int64_t in[10];
+               double out;
+       } tests[] = {
+               { .in = { 2, 2, 2, -1 }, .out = 0.0 },
+               { .in = { -1 }, .out = 0.0 },
+               { .in = { 1, 2, 3, 4, 5, 6, 7, 8, -1 }, .out = 5.25 },
+       };
+
+       struct stats_dist *t;
+       unsigned int i, j;
+
+       test_begin("stats_dists_get_variance");
+
+       for (i = 0; i < N_ELEMENTS(tests); i++) {
+               t = stats_dist_init();
+               for (j = 0; tests[i].in[j] >= 0; j++) {
+                       stats_dist_add(t, tests[i].in[j]);
+                       test_stats_dist_verify(t, tests[i].in, j+1);
+               }
+               test_assert_idx(DBL_EQ(stats_dist_get_variance(t),
+                                      tests[i].out), i);
+
+               stats_dist_deinit(&t);
+       }
+
+       test_end();
+}
+
 void test_stats_dist(void)
 {
        static int64_t test_input1[] = {
@@ -96,4 +127,6 @@ void test_stats_dist(void)
        test_assert(stats_dist_get_95th(t) > 0 && stats_dist_get_95th(t) < i-1);
        stats_dist_deinit(&t);
        test_end();
+
+       test_stats_dist_get_variance();
 }